/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.solr.servlet;

import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * A Simple redirection servlet to help us deprecate old UI elements
 */
public class RedirectServlet extends HttpServlet {

	static final String CONTEXT_KEY = "${context}";

	String destination;
	int code = HttpServletResponse.SC_MOVED_PERMANENTLY;

	public void init(ServletConfig config) throws ServletException {
		super.init(config);

		destination = config.getInitParameter("destination");
		if (destination == null) {
			throw new ServletException(
					"RedirectServlet missing destination configuration");
		}
		if ("false".equals(config.getInitParameter("permanent"))) {
			code = HttpServletResponse.SC_MOVED_TEMPORARILY;
		}

		// Replace the context key
		if (destination.startsWith(CONTEXT_KEY)) {
			destination = config.getServletContext().getContextPath()
					+ destination.substring(CONTEXT_KEY.length());
		}
	}

	public void doGet(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {

		res.setStatus(code);
		res.setHeader("Location", destination);
	}

	public void doPost(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {
		doGet(req, res);
	}
}